Networking hardware, also known as network equipment or computer networking devices, are physical devices which are required for communication and interaction between devices on a computer network. Specifically, they mediate data in a computer network.[1] Units which are the last receiver or generate data are called hosts or data terminal equipment.

The most common kind of networking hardware today is a copper-based Ethernetadapter which is a standard inclusion on most modern computer systems. Wireless networking has become increasingly popular, especially for portable and handheld devices.

Taking a wider view, mobile phones, PDAs and even modern coffee machines may also be considered networking hardware. As technology advances and IP-based networks are integrated into building infrastructure and household utilities, network hardware will become an ambiguous term owing to the vastly increasing number of "network capable" endpoints.

Router: a networking device that forwards data packets between computer networks. Routers perform the "traffic directing" functions on the Internet. A data packet is typically forwarded from one router to another through the networks that constitute the internetwork until it reaches its destination node.[3] It works on OSI layer 3.[4]

Switch: a device that connects devices together on a computer network, by using packet switching to receive, process and forward data to the destination device. Unlike less advanced network hubs, a network switch forwards data only to one or multiple devices that need to receive it, rather than broadcasting the same data out of each of its ports.[5] It works on OSI layer 2.

Hub: for connecting multiple Ethernet devices together and making them act as a single network segment. It has multiple input/output (I/O) ports, in which a signal introduced at the input of any port appears at the output of every port except the original incoming.[1] A hub works at the physical layer (layer 1) of the OSI model.[7] Repeater hubs also participate in collision detection, forwarding a jam signal to all ports if it detects a collision. Hubs are now largely obsolete, having been replaced by network switches except in very old installations or specialized applications.

Repeater: an electronic device that receives a signal and retransmits it at a higher level or higher power, or onto the other side of an obstruction, so that the signal can cover longer distances.[8]

Firewall: a piece of hardware or software put on the network to prevent some communications forbidden by the network policy.[12] A firewall typically establishes a barrier between a trusted, secure internal network and another outside network, such as the Internet, that is assumed to not be secure or trusted.[13]

Network address translator (NAT): network service (provided as hardware or as software) that converts internal to external network addresses and vice versa.[14]

Other hardware devices used for establishing networks or dial-up connections include:

Multiplexer: a device that selects only one signal from several electrical input signals.

Modem: device that modulates an analog "carrier" signal (such as sound) to encode digital information, and that also demodulates such a carrier signal to decode the transmitted information. Used (for example) when a computer communicates with another computer over a telephone network.